Quantum dots (QDs) are a type of nanoparticles containing Group II-VI or Group III-V elements, and have characteristics such as broad absorption spectra, narrow emission bands, tunable color purity, high fluorescence quantum yields, etc.
Quantum dot light-emitting devices typically have two excitation mechanisms. In a direct carrier injection mechanism, holes from a hole transport layer and electrons from an electron transport layer are respectively injected into a quantum-dot light-emitting layer, and form excitons for light emission. In an energy transfer mechanism, excitons formed at the transport layer directly transfer energy to quantum dots for light emission.
Current QD light-emitting diodes (LEDs) typically include a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and a quantum dot light-emitting layer. Current design and manufacturing of quantum dot light-emitting devices have focused on optimization of layer structures such as the HIL, HTL, ETL, etc.